Hi there,
I have different machines with windows7 and the program will sit in task manager for a long time, 20 minutes usually, then it launches and works fine. I have this issue only with sketchup.
No temp issues, .net e c++ updated. GPU updated. Windows updated.
Look at the active processes your anti-virus program is monitoring (do that when SU is launched.) It maybe trying to block it and waiting for input from you. I can r-click on the antivirus icon in the notification tray area in the taskbar and go right to its active process dialog.